In 1987, JL. Cox (5 Stand-alone surgery f…)described one of the most effective treatments for rhythm control in AF: the maze procedure or Cox-maze technique. This procedure aimed to isolate or disrupt all electrical mechanisms underlying AF, enabling sinus impulses to activate the entire atrium in an orderly manner. This isolation was achieved through a “cut and sew” technique on specific atrial regions identified in prior animal studies (5 Stand-alone surgery f…).

Iterations aimed at reducing block risk led to the development of Cox-maze II and Cox-maze III. Despite its high efficacy, the maze surgery was complex and not without risk due to the cut-and-sew nature of the procedure. Alternative energy sources emerged, allowing lesion sets to be created using radiofrequency and/or cryoablation (Cox-Maze IV), thus reducing risks associated with cut and sew (5 Stand-alone surgery f…)and broadening indications.

In the 1990s, Haïsaguerre et al. (5 Stand-alone surgery f…)found that radiofrequency catheter isolation of the pulmonary veins could interrupt paroxysmal AF, leading to a rise in percutaneous techniques. Meanwhile, atrial arrhythmia surgery, due to its invasiveness, was limited to procedures where it could be performed concomitantly with surgery for another structural or coronary condition.

In the last decade, however, reports of high recurrence following catheter ablation for persistent and long-standing persistent AF have emerged (5 Stand-alone surgery f…). Concurrently, new minimally invasive thoracoscopic approaches have renewed interest in stand-alone atrial arrhythmia surgery. For example, the latest European guidelines recommend stand-alone thoracoscopic AF surgery (IIa/B) for patients with paroxysmal or persistent AF refractory to antiarrhythmics who have a recurrence or high recurrence risk after catheter ablation (5 Stand-alone surgery f…).

Thoracoscopic stand-alone AF ablation relies on two principles: left atrial posterior wall isolation and electrical/mechanical exclusion of the left atrial appendage. Additionally, depending on AF substrate, patient characteristics, team technical expertise, or the setting (hybrid operating room vs. standard OR), additional lesions may be made in the right atrium, the coumadin ridge (a normal variant separating the superior left pulmonary vein ostium from the LAA), or the left atrial isthmus.

Unipolar or bipolar radiofrequency is used in thoracoscopic AF ablation. Technologies for electrically isolating the left atrial posterior wall include:

The classic box lesion (posterior wall and pulmonary vein isolation) with the Cardioblate Gemini™ (Medtronic™, Minnesota, USA) (5 Stand-alone surgery f…)or combining Isolator Sinergy Clamp™ bipolar radiofrequency clamps (AtriCure™, Minnesota, USA) for the pulmonary veins and Coolrail™ linear pen (AtriCure™, Minnesota, USA) (5 Stand-alone surgery f…)for left atrial posterior wall roof and floor lesions. This procedure electrically disconnects the left atrial posterior wall and pulmonary veins and ablates the coumadin ridge and Marshall ligament. Depending on devices and techniques, this lesion set can be achieved with a unilateral or bilateral approach using three ports. Compared to percutaneous ablation, the effectiveness is significantly higher. For instance, the FAST trial by Castellá et al. reported a 56% recurrence rate at 7 years for thoracoscopic patients versus 87% for catheter-based approaches (5 Stand-alone surgery f…). Stand-alone posterior wall ablation with the Episense™ system (AtriCure™, Minnesota, USA) (5 Stand-alone surgery f…). This technique involves unipolar radiofrequency isolation of the posterior wall via a subxiphoid approach. It requires percutaneous pulmonary vein ablation, thus considered part of a hybrid rather than a stand-alone approach. One-year AF survival with this technique was 68%, versus 50% for catheter ablation, as shown in the randomized CONVERGE trial (5 Stand-alone surgery f…).

In all cases, surgical exclusion of the LAA reduces thromboembolic complications. Methods for LAA occlusion include automatic staplers and clips (AtriClip™, AtriCure™, Minnesota, USA) (5 Stand-alone surgery f…), though clips appear safer with more reproducible implant success . Surgical LAA exclusion not only prevents thrombus formation but also achieves electrical isolation, unattainable with catheter-based devices, significantly reducing arrhythmia recurrence  (5 Stand-alone surgery f…).

Decision-making in symptomatic, refractory AF or high-risk patients post-optimal medical therapy and pulmonary vein catheter ablation is complex. Emerging technologies, such as pulsed-field ablation , show promise, though the effect of mechanistic approaches, such as “driver” ablation , remains undetermined. In this context, thoracoscopic AF surgery should be considered an additional step in patient management rather than an alternative. Hybrid programs combining percutaneous and minimally invasive surgical ablation in high-expertise centers may provide effective solutions for persistent or long-standing persistent AF patients, for whom medical or catheter treatments yield poor outcomes.

At the 2023 European Heart Rhythm Association Congress, results from the CEASE AF trial  (available at https://esc365.escardio.org/presentation/265325) were presented, comparing hybrid surgical and percutaneous approaches versus percutaneous-only ablation in AF patients with no previous ablations. The principal investigator (Nicholas Doll, Schüchtermann Clinic, Bad Rothenfelde, Germany) reported an 83% relative risk reduction in AF recurrence with the hybrid arm versus catheter alone.

In Spain, AF surgery (stand-alone or concomitant) is underutilized compared to other European countries and the United States . This may be due to advanced AF stage at referral, economic constraints, lack of training, or limited awareness of the technique within the cardiology community. However, given the current scientific evidence, available technology, and growing demand for symptomatic AF treatment, there are increasingly more reasons—and fewer excuses—to support atrial fibrillation surgery.

REFERENCES:

1. Cox JL. The surgical treatment of atrial fibrillation. IV. Surgical technique. J. Thorac. Cardiovasc. Surg. 1991;101:584-92.
2. Smith PK, Holman WL, Cox JL. Surgical treatment of supraventricular tachyarrhythmias. Surg Clin North Am 1985;65:553-70.
3. Robertson JO, Lawrance CP, Maniar HS, Damiano RJ. Surgical techniques used for the treatment of atrial fibrillation. Circ J 2013;77:1941-51.
4. Haïssaguerre M, Jaïs P, Shah DC, Takahashi A, Hocini M, Quiniou G, et al. Spontaneous initiation of atrial fibrillation by ectopic beats originating in the pulmonary veins. New England Journal of Medicine 1998;339:659-66.
5. Packer DL, Mark DB, Robb RA, Monahan KH, Bahnson TD, Poole JE, et al. Effect of catheter ablation vs. antiarrhythmic drug therapy on mortality, stroke, bleeding, and cardiac arrest among patients with atrial fibrillation: the CABANA randomized clinical trial. JAMA 2019;321:1261-74.
6. Hindricks G, Potpara T, Dagres N, Arbelo E, Bax JJ, Blomström-Lundqvist C, et al. 2020 ESC Guidelines for the diagnosis and management of atrial fibrillation developed in collaboration with the European Association for Cardio-Thoracic Surgery (EACTS):  The Task Force for the diagnosis and management of atrial fibrillation of the European Society of Cardiology (ESC) Developed with the special contribution of the European Heart Rhythm Association (EHRA) of the ESC. Eur Heart J 2021;42:373-498.
7. Schenk S, Terne A, Fritzsche D. Five-box thoracoscopic maze based on the Gemini-S bipolar ablation device to treat atrial fibrillation. Multimed Man Cardiothorac Surg 2021;2021.
8. Carnero-Alcázar M, Maroto-Castellanos L, González-Ferrer JJ. Stand-alone surgery for atrial fibrillation. Rev Esp Cardiol (Engl Ed) 2023;76:398-401.
9. Castellá M, Kotecha D, van Laar C, Wintgens L, Castillo Y, Kelder J, et al. Thoracoscopic vs. catheter ablation for atrial fibrillation: long-term follow-up of the FAST randomized trial. Europace 2019;21:746-53.
10. DeLurgio DB, Crossen KJ, Gill J, Blauth C, Oza SR, Magnano AR, et al. Hybrid convergent procedure for the treatment of persistent and long-standing persistent atrial fibrillation: results of CONVERGE clinical trial. Circ Arrhythm Electrophysiol 2020;13:e009288.
11. Bedeir K, Warriner S, Kofsky E, Gullett C, Ramlawi B. Left atrial appendage epicardial clip (AtriClip): essentials and post-procedure management. J Atr Fibrillation 2019;11:2087.
12. Whitlock RP, Vincent J, Blackall MH, Hirsh J, Fremes S, Novick R, et al. Left atrial appendage occlusion study II (LAAOS II). Can J Cardiol 2013;29:1443-7.
13. Di Biase L, Burkhardt JD, Mohanty P, Mohanty S, Sanchez JE, Trivedi C, et al. Left atrial appendage isolation in patients with longstanding persistent AF undergoing catheter ablation: BELIEF trial. J Am Coll Cardiol 2016;68:1929-40.
14. Mathuria N. Pulsed-field ablation for atrial fibrillation: the future is now? JACC Clin Electrophysiol 2021;7:628-9.
15. Quintanilla JG, Shpun S, Jalife J, Filgueiras-Rama D. Novel approaches to mechanism-based atrial fibrillation ablation. Cardiovasc Res 2021;117:1662-81.
16. CEASE AF: Primary Efficacy and Safety Endpoints [Internet]. [citado 2023 may 28]; Available from: https://esc365.escardio.org/presentation/265325
17. Carnero-Alcázar M, Cuerpo-Caballero G, López-Menéndez J, Centella-Hernández T, Polo-López L, García- Fuster R, et al. Cirugía cardiovascular en España en el año 2021. Registro de intervenciones de la Sociedad Española de Cirugía Cardiovascular y Endovascular. Cirugía Cardiovascular [Internet] 2023 [citado 2023 may 28];Available from: https://www.sciencedirect.com/science/article/pii/S1134009623000499